button{
    margin-left: 40px;
    margin-top: 20px;
    width: 100px;
    font-size: 15px;
    height: 30px;
    border: none;
    border: solid 2px green;

}
li{
    margin: 5px;
    color:red;
    font-size: 18px;
    border: 1px solid green;
    width: 550px;
}
ul>li.gujia{
    width: 535px;
    background-color: #ccc;
}